PROPELLER HELP!!

[mvp111]

2016 Bayliner 19ft Deck boat with 150 Mercury four stroke.
With factory 3 blade Aluminum prop 14.5 x 21 = 50mph @ 5300 rpm
Changed to a Turning Point SS 14.5 x 21 = 41 mph @ 5300 rpm.
Why is this and where do I go from here with a SS prop.
Thanks

 

[Sea Rider]

Probably a blade size, shape, thickness & weight issue, that's why I like maximizing engines with original props in less pitch sizes.....factory have tested all their OEM props properly on water trails. Sometimes going for other brands props can be a shot in the air along damping money straight into the deep blue..

Happy Boating

 

[QBhoy]

Doesn't make much sense to me, if all variables were even between the two tests.
The standard prop from Merc is probably a black max. A pretty decent prop all round.
A cheaper stainless is sometimes not worth having.
Try a laser 2 21" and you will see a difference.
We're both speeds gps ? 50mph is pretty quick.

 

[jimmbo]

The numbers don't add up

 

[walleyehed]

The numbers don't add up

At all....